1. Field of the Invention
The present invention relates to a method for treating varicose veins. More particularly, the present invention relates to a method of utilizing laser energy delivered into the vessel lumen via endovascular techniques to treat varicose veins.
2. Description of the Prior Art
The use of lasers in the treatment of vascular disease has been gaining rapid interest. Lesions such as port wine stains, facial telangiectasias, and some lower extremity veins have been treated externally by lasers with some success. Most of these laser procedures irradiate the surface of the skin with laser energy that penetrates the skin, is absorbed by the blood, and coagulates and collapses the blood vessel.
Larger varicose veins are located deeper in the soft tissues. Such veins have not been successfully treated with laser techniques. It is believed that treating such larger veins with laser energy delivered from the surface would require higher powers that could lead to increased side effects including scarring and skin hyper- or hypopigmentation.
Current accepted treatments of varicose veins include sclerotherapy, ambulatory phlebectomy, and ligation and stripping of the greater saphenous vein in cases of saphenofemoral junction incompetence. Although there has been wide variation in reported results of sclerotherapy treatment of the greater saphenous vein when saphenofemoral junction reflux is present, most studies report recurrence rates of 30% to 70% after 5 years. The existing standard for the treatment of saphenofemoral junction reflux is limited ligation and stripping of the greater saphenous vein.
The obvious drawbacks of traditional surgical therapy include the increased risks and costs associated with more extensive anesthesia because general anesthesia is normally used during varicose vein surgery, instead of local anesthesia. In addition, there are possible complications of the surgery that include bleeding, infection, hypertrophic scars, ankle paresthesia, and a prolonged recovery period. Ambulatory phlebectomy for treatment of saphenopopliteal junction reflux or isolated perforator incompetence is less invasive than ligation and stripping and can be done with local anesthesia. However, complications incident to the surgical procedure may still occur.
The search for less invasive techniques to treat varicose veins with acceptable short and long term results has led to the development of additional treatment modalities. These modalities include ultrasound guided sclerotherapy (echo sclerotherapy), monopolar electrocautery, and a bipolar radio frequency based energy source delivered by a disposable catheter (VNUS).
Although, perhaps more invasive than surface laser irradiation, there are potential advantages to delivering laser energy from below the skin. Such advantages include a decrease in thermal damage to intervening tissue and minimization of the possible side effects to the skin itself.
In Spanish Patent No. 9701586 to Salat et al., electricity is used to treat varicose veins. The Salat et al. patent describes an endoluminal electrocoagulator for varicose vein operations. The microsurgical instrument contemplated by that invention is essentially based on the use of an electrocoagulating microhead joined to a conductor wire with adequate flexibility to be inserted percutaneously. The use of electricity inevitably leads to coagulation of blood within the blood vessel rather than causing fibrosis of the blood vessel itself. However, it has now been found that fibrosis of the blood vessel is preferred because veins of a much larger diameter may therefore be treated safely and effectively.
In U.S. Pat. No. 4,564,011 to Goldman, laser energy is delivered from below the skin. The Goldman patent provides using laser energy delivered via a hollow needle insertable within a blood vessel to create a blood clot. The Goldman patent also provides using laser energy immediately adjacent to a damaged blood vessel for creating white scar tissue which tends to push against the vessel, thereby causing the vessel to shrink in size and at least partially disappear from view. This requires that each single point of damage be treated separately.
In U.S. Pat. No. 5,531,739 to Trelles, laser energy is delivered again from below the skin. The Trelles patent discloses a method in which laser energy is delivered via a fiber optic probe to a location underneath a blood vessel to be treated. The vessel is irradiated with a treatment beam having a fluence sufficient to coagulate and collapse the vessel at that location. Yet, again, this procedure must be repeated at multiple sites along the length of the blood vessel so that it will collapse along its length and no longer carry any blood.
In U.S. Pat. No. 5,053,033 to Clarke, laser energy is delivered endoluminally. The Clarke patent describes using laser energy in the range about 240 nanometers to about 280 nanometers delivered via an optical fiber or other waveguide incorporated, for example, into a percutaneous catheter. In operation, the ultraviolet laser energy kills smooth muscle cells at an angioplasty site, thereby reducing the risk of restenosis, while minimizing damage to surrounding tissue. However, this technique is used to keep a blood vessel open and, therefore, has little use in the treatment of varicose veins.
In U.S. Pat. No. 5,161,526 to Hellwing et al., laser energy in the wavelength range of 500 nanometers to 1100 nanometers is used. The Hellwing et al. patent describes using laser energy to aid in the treatment of hemophilia by biostimulating muscles and joints. However, this method delivers the laser energy from the surface of the skin. Thus, blood vessels in the treatment area remain unaffected.
In U.S. Pat. No. 5,707,403 to Grove et al., laser energy is used to affect blood vessels. In the Grove et al. patent, laser energy is delivered at the surface of the skin in the wavelength range 700 nanometers to 1100 nanometers. Blood vessels within the first 2 millimeters of the dermis can be treated with this method, otherwise the high fluence or energy can cause explosion of surface vessels and burning of the skin. Furthermore, the delivery of laser energy at the surface of the skin inevitably causes coagulation of blood within the blood vessel rather than causing fibrosis of the blood vessel itself.
Endovascular delivery of laser energy would decrease the amount of power necessary to treat the vein and virtually eliminate the potential for adverse side effects to the overlying skin and intervening tissues. In addition, fibrosis of the blood vessel is preferred because veins of a much larger diameter may therefore be treated safely and effectively.
Accordingly, a need exists for an endovascular laser treatment of varicose veins using laser energy in order to produce direct endothelial and vein wall damage with subsequent fibrosis.
It is an object of the present invention to improve the method of the treatment of varicose veins.
It is another object of the present invention to provide such a method that decreases varicose vein recurrence rates.
It is still another object of the present invention to provide such a method that causes direct endothelial and vein wall damage with subsequent fibrosis.
It is a further object of the present invention to provide such a method that introduces a fiber optic line into the vein lumen to deliver intraluminal laser energy with direct contact of the tip of the fiber optic line with the vein wall.
It is yet another object of the present invention to provide such a method that avoids blood clot formation and maximizes vein wall damage.
These and any other objects of the present invention are achieved by a method for treating varicose veins using a tipped laser energy carrier to deliver laser energy into the blood vessel lumen to produce direct endothelial and vein wall damage with subsequent fibrosis. By delivering laser energy intraluminally, the entire thickness of the vein wall is damaged. This results in fibrosis of the vein and a decrease in the diameter of the varicosity. Preferably, the vein wall will be damaged to the extent that the subsequent fibrosis causes the vein to collapse.